Regulator.



L. W. THOMPSON.

REGULATOR.

APPLIIjATIOIl ,FILED Ill. 22. l9l3. RENEWED API. 29. ISIS.

1,251,446. Patented Dec. 25,1917.

WITNESSES:

Lou/3 W Thom won INVENTOR UNITED STATES PATENT OFFICE.

LOUIS w. THOMPSON, OF WILKINSBUBG, PENNSYLVANIA, ASSIGNOB TO GENERALELECTRIC COMTANY, A CORPORATION OF NEW YORK.

REGULATOR.

Specification of Letters Patent.

Patented Dec. e5, 1917.

Application fled latch 22, 1913, Serial No. 756,068. Renewed April 29,1916, Serial No. 94,518.

To all whom it may concern:

Be it known that I LomsW. Tuoarrson,

My invention relates to regulators thatare adaptedto be employed inconnection with dynamo electric machines for automatically regulatingthe effect of a resistance by intermittently short-circuiting the same.It has lators of the v1 rating type which efiect'the regulationofgenerator voltage by controlling the field strength of the erators.Llectric regulators of the vibrating have long been used for controllingthe e d current of dynamo-electric machines for the pur se of controllintheir operation as reaar s speed, voltage, oad, power factor, etc. ne ofthecnief difliculties encountered in the use of this type of regulatoris an excessive sparking at the contacts, which ultimately so in uresthese contacts that their operation is imperfect and unsatisfactory.Large contacts cannot be satisfactorily used because of the increase inweight. This difficulty is commonly overcome by using a.

plurality of synchronously operated relays, each of which short-circuitsonly a portion of the whole resistor, so that the potential differenceacross each pair of ;contacts is reduced. Further difiiculty has beenoncountered-in so arrangin the moving contacts that the surgestechnically known as hunting are prevented.

My invention comprises a regulator of the vibrating type in whichsparking at the contacts is prevented, while the use of a plurality ofrelays is avoided. To this end I short circuit a resistor by means ofalternative, or transfer, circuits, each of which comprises a periodiccircuit interrupter of rugged construction in series with vibratorycontacts. The vibration of said contacts is effected and controlledjointly by the quantity to be regulated, and b the periodic circuitinterrupter. These evices are s o arranged that said alternative, ortransfer, circuits arealrways' broken by the periodic circuit'interrupter.

A further object of my invention is to provide a novel and improvedarrangement articular reference to regufor the prevention of hunting.For this purpose I provide, in connection with the combination ofvibrating contacts a periodic circuit interrupter, a resilient membertending, when stremed, to open the vibrating contacts and a device forstressing said resilient member which is set in action upon the closingof the circuit throu h said device and put out of action by t e openingof the periodic circuit interrupter.

The single figure-of the drawings is a diagrammatic view of circuits andapparatus showing my invention asapplied to the regulation of thevoltage of an alternating current generator through regulating the fieldcurrent of its exciter.

Referring to the drawings, an electrical circuit, the voltage of whichit is desired to maintain substantially constant,,comprises lineconductors 1 and 2, and is supplied from an alternating currentgenerator 3. The field winding 4 of the generator is energized by anexciter 5 which is here indicated as a direct current shunt woundgenerator.

The exciter 5 is provided with a shunt field windin 6 and a fieldresistor 7 in series therewit The main circuit of the exciter comprisesavariable resistor 8 which may be adjusted to control the current in thecircuit.

M regulator, as shown, comprises means for intermittently shortircuiting the field resistor for varying len hs of time, depending uponan electric condition of the circult including tl conductors 1, 2. Saidmeans comprise relatively 'm'ovable contacts which may have any one of avariety of forms, but, as illustrated, comprise resilient switch members9 and 10, the extremities of which are provided with contact memberswhich coact respectivel tact members 11, 12 an 13, 14. The switchmembers 9 and 10 are actuated by movable members 15 and lfirespectively, and are adapted, due to their yielding character, topermit some movement of the members 15 and 16 after engagement of thecontact members carried thereby with the contact members 11, 12 and 13,14 respectively. The core members are each provided with two coils 17and 18.

The coils 17 are in series with each other and with the secondarywinding 19 of :1 voltage transformer 20, the primary winding 21 of whichis connected across the line of the alternator 3. The coils 18 areconnected in series with each other and with the' secondary winding 22of a current transformer 23. the primary winding 24 of which is inseries with the line conductor 1. The transformers 2O and-23 are'madewithout cores or with.

smallcores to reduce the. inductance and thereby decrease the timerequired for an impulse to be transmitted by the transformers whichserve as butters and also to impart an upward movement to'said mres whenthe windings 25 are subsequently dei nergized. A pair of periodiccircuit interrupting devices 27 com rises rotatable drums '28 providedwith a tomato sections of oonducting material 29 and insulating material30. .\s here shown, four sections of each material are used, theoppositb sections of conducting material being cross-connected in orderthat oppositel arranged brushes 31 may be con: nected w ten sections ofconducting material are engaged by the respective brushts. The

conductor sections are arranged to project from thewheel in order that,as the drmns rotate, a quick break may lie-obtained at the brushespwhichmay be yieldingly purist-d inst the drums 28 by any suitable means. T edrums are arran to be rotated by any suitable source wlnch'may beconnected to a rotating part of the system or may be independent asdesired. It will be noted the drums are arranged to rotate 45 degreesapart in order that one pair of brushes will be in engagement. with apair of contacts on one :lrum when the other pair of brushes is out ofengagement with the contacts on the other drum, the conditionsalternating as the drums rotate. The circuit interruptcrs 27 control theenergization of the. windings 25 and prevent the disbngagemcnt of thecontacts carried by the switch members 9 and 10 from contacts 11, 12 and13, 1-1 respecmay, while current is passing therethrongh, and anyequivalent construction may, of course, e'employed.

'lhe'ope-ra-tlon ofmy invention, as at present understood, is asfollows: Assume for purposes of explanation that it is desired tomaintain the voltage of the. circuit 1, 2 at. a predetermined value andthat the various elements of the system are adjusted for this value.Also disregard for lho moment the effect of the compensating windings18, 18,

the exciter, the voltage of the circuit 1, 2

will be less than the desired value, whereas, .if a short circuit becontinually maintained around said resistance 7, the voltage of thecircuit 1, 2 will have a value greater than that desired. If the voltageof the circuit 1, 2 he. sulliciently high. the cores 15 and 16 will beraised to a position in, which the contacts carried by the switchmembers 9 and 10, secured thereto. will be maintained out of contactwith the contacts 11. .12 and 13, 14. The resistance. 'i' willaccordingly be rendered effective and hence the voltage of the circuit1:2 will decrease. \Vhcn a certain decrease in voltage has occurred, thecore members 15 and 16 will lower so that the contacts carried by theswitch members J and 10 will engage with the contacts 11, 1:2 and 13.14. During the period of such eugagement. the resistance 7 will be shortcircuited through alternative circuits, one of which comprises, the.conductor 32. contact 12. switch nu-mber 9. contact 11, lefthand whaling25. and the left-hand interrupter 27. and the other of which comprisesthe conductor 32. contact 13. switch member 10, c 'mtact l-t. right-handwinding Q5. and the right-hand interrupter :27. The field current of theexciter will thus be transferred from the circuit comprising one.interrupter totlucircuit comprising the other interrupter. \Vhcn thecircuitis closed through a. winding :25. the core member associatedtherewith will be drawndown so that it; will compress the-spring :26associated there with and will also flex the switch member 9 or 10,asthe. case may be. causing the contacts carried by the. same to firmlyengage with the. contacts 11. 12 or .13. H. On the drawing, the switchmember 9 is shown flexed in the manner described. since the circuitthrough the -lcfthnnd winding 25 is closed. If now, the voltage of thecircuit 1, .2 rise to. or above. the desired value. the increasedenergization'otthe windings 17. 17

will tend to raise the cores l3 and 16 and lift the. contacts carried bthe switch members 9 and 10 out of engagement with the contacts ll, 12and l3. l4. ll the iuterrupters. at the. moment. the. circuit voltagereaches this value. are. in the position shown. the. con

their coiiperating Stationary contacts, the ref sistance 7 will becomeefi'ective and the voltage ofthe circuit 1, 2- will consequentlydecrease. The cores 15 and 16 will there .fore lower and a circuit inshunt to the resistance 7 will be completed through that interrupter,which at the instant has a pair. of contacts 29 in engagement'with apair of brushes 31, and the winding "25 in circuit with suchinterru ter.Assume that, at this instant, the rightand interrupter has a pair ofcontacts 29 in engagement with the brushes 31. 1 The shunt circuit willtherefore be completed through such ri hthand in: terrupter,'the ri'ht-hand win ing 25, the contact '14, switc member 10, contact 13, andthe lead 32. The resistance 7 being short circuited the voltage of'the'circuit 1,

- 2 will increase. The right-hand winding 25 being energized, the s ring26 will be comand the switc member 10 will be exed in the mannerpreviously described. In this waythe core members 15 and 16 are causedto vibrate vertically, and if 'the voltage of the circuit 1, 2 is belowthe desired value, the riod, at each vibration, during which a ortcircuit around the resistahce 7 exists is greater than the period duringwhich'such a short circuit exists when the voltage of the circuit 1, 2has the desired value and, on the other hand, if the voltage of thecircuit 1, 2 be above the desired value the riod during which a shortcircuit around t e resistance 7 exists is less than the period duringwhich such short circuit exists when the voltage of the circuit 1, 2 hasthe desired-value. It is also evident that the switch members 9 and 10can never be opened until afterthe respective circuits in which they areincluded are opened by the interrupter. Thus sparking between the switchmembers 9 and 10 and their respective contacts is wholly eliminated.

The effect of the compensating coils 18 will now he explained. When aheavy load i thrown on the supply circuit, there will be an increase inthe drop in potential due to line resistance. It is usually desirable tomaintain a substantially constant voltage at the points of currentsupply and inorder to efi'ect this result; the generator voltage must beincreased to compensate for the line drop. The compensating coils 18 arearranged to provide for the necessary modifications of the effectsproduced by the coils 17. An incrcase'in the flow of current in the lineconductor 1 will cause a corresponding insultant effect may be eitherthe sum or dif- 'of a resilient member, means responsive to crease inthe secondary winding 22 of the transformer 23 and in the energizationof the coils 18. The coils 18 are so wound that an increase in currenthas the effect of opposing the upward movement of the core members and,as before explained, the relativel longer period of closure of theswitch mem ers 9 and 10 will cause an increase in the generator voltage.When the current decreases, this effect is diminished and when no loadis on the line, the compensating coils have no effect. Thus, it will beunderstood that the'coils 17 and 18 have independent effects-upon thecore members but the reference of the independent efi'ects according toline conditions.

It will be understood that many changes will occur to one skilled in theart. Such changes as fall within the limits of the appended claims maybe made without de--. parting from the spirit of my invention.

I claim as my invention:

1 An electric regulator comprising a re-v sistor, relatively movablecontacts responsive to the quantity to be regulated, means for holdingsaid contacts in engagement, a pcriodic circuit interrupter anda'circuit for shunting said resistor comprising said contacts, holdingmeans, and circuit interrupter.

2. 'An electric regulator comprising a resister, relatively movablecontacts responsive to the quantity to be regulated, 'means for holdingsaid contacts in engagement, resilient means put under tension by theaction of said holding means, a periodic circuit interrupter, and acircuit for shunting said resistor ,comprising said contacts, holdingmeans, and circuit interrupter.

3.-An electrical regulator comprising a 1,5 resistor, relatively movablecontacts responsive to the quantity to be regulated, one of saidcontactsbeing resiliently mounted, means for holding said contacts inengagement and putting said resilient mount ng under tension, a'periodic circuit interrupter, and a circuit for shunting said resistorcomprising said contacts, holding means, and circuit interrupter.

4. An electric regulator comprisin a rc- 116 sistor, two sets ofrelatively movab e contacts, each of which is responsive to the quantityto be regulated, at periodic circuit interrupter in series with each setof contacts, said circuit interrupters being ar- 129 ranged so that onewill be open when the other is closed and alternative circuits forshunting said resistor, each of which comprises a periodic circuitinterrupter and a pair of contacts.

5. An electrical regulator comprising a resistor, a pair of relativelyfixed contacts, a pair of movable contacts associated therewith andelectrically connected by means the quantity to be regulated associatedwith said resilient member intermediate said contacts, a coil in serieswithsaid contacts arranged, when energized, to hold said con;- tncts inen gement and put said resilient member un er tension, rupter, and acircuit or shunting said resistor comprising said contacts, series coil,and circuit interru ter.

6; The combination with a main electrical circuit-comprising agenerator, of a field winding therefor, meansfor controlling theexcitation of said winding comprisin a circuit, said circuit includinga-peri ic circuit interiilpter and a switch membervthat is res xmsive tothe current and the voltage values of said main circuit and toconditions in the circuit'of said field winding.

7. The combination with a crater, of a field winding therefor xneans'iii controlling the excitation of: windingioomprising a circuit includinga periodic circuit interrupter and a switch member responsive to anelectrical condition'of said generator and conditions in the circuit ofsaidfield 8. The combinationwith a generator having a fieldmagnetwinding and a resistor iii circuit therewith, 'of meansfor,shunting said resistor comlf a periodic circuit interrupter, a co incircuit 'with said circuit interrupter, and a inovable core member bysaidcoil.

riodic circuit intcr- 9. An electric regulator comprising a resistor, aplurality of periodic clrcuit interrupters, a plurality, of vibratorymembers,

and a plurality of transfer circuits in shunt to' said resistor andadapted to be jointly controlled by mid circuit interrupters and saidvibratory members.

10. An electric regulator comprising a rcsister, a pair of circuits inshunt to said resistor, a pair of periodic circuitinterrupters adaptedto alternately open said circuits, and a. pair of vibratory membersadapted to be controlled both b the quantity to be regulated and by saiinterru ters for controlling the continuity of sai circuits.

11. An electric regulator comprising a resistor, a pair of circuits inshunt to said resistor, a pair of periodic circuit interrupters adaptedto alternately open said circuits, and a vibratory device, associatedwith each of said circuits,comprising a winding and vibratory contacts,in series therewith, and a winding adapted to be energized in responseto the quantity to be lated.

In testimony whereof, -I have hereunto subscribed my name this 20th dayof March,

LOUIS w. THOMPSON.

wanes-es? J. R. Laxomr, B. B. Hrnrs.

